What Cream Should I use to Prevent Acne because my Skin is Acne Prone?
You can certainly start with things that are over-the-counter. These include mostly salicylic acid washes or benzoyl peroxide washes. There's a PanOxyl bar, for example, that has a very low percentage of benzoyl peroxide. That's a good place to start for very mild acne treatment. If you still notice breakouts after the PanOxyl bar, then I'd recommend seeing a board certified dermatologist.
What Moisturizer Should I Use?
It's most important that you find a moisturizer that is mineral oil free. I typically find ceramide moisturizers to be the most effective. Most notably, First Aid Beauty's 5 in 1 Moisturizer or 5 in 1 Face Cream can be very helpful for patients. They contain an SPF factor and also can be a good emollient; it prevents acne flares.